[media] cx25840: convert max_buf_size var to lowercase
[media] cx25840: convert max_buf_size var to lowercase

CodingStyle fix: vars should be in lowercase.

Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@osg.samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs